IPTables labeling and user roles

[Konstantin Ryabitsev]

Hi, all:

Here's an interesting idea I had. Let's say my users have two ways of 
logging in to the systems -- one via a VPN that requires 2-factor 
authentication, and another directly via ssh using their public key.

Is there a way to use pam in conjunction with iptables packet labeling 
to make sure that if the users logged in via VPN, they get user_u, but 
if they went directly, they only get guest_u?

Or, simiarly, if a sysadmin logs in via the VPN that required 2-factor 
authn, they get sysadm_u, and if directly, then just user_u?

I think that would be kinda neat, but I'm not sure it Works That Way 
(TM).

Best regards,